20 percent.
Since one strand is 20, the opposite that would connect with it (Thymine) would have the same amount so the total would be 100.
Hope this helps!
According to a source the answer is <span><u>Cyanobacteria were the first organisms to produce oxygen in water, which then escaped into the atmosphere.</u>
These cyanobacteria species were the first ones to "produce" oxygen as a by-product of the photosynthetic mechanisms which enables organisms to make their own food. </span>
Vascular Plants co<span>ntain tubes that help transport water and nutrients into their other parts.</span>
Vascular tissue in plants is made of two specialized conducting tissues: xylem, which conducts water, and phloem, which conducts sugars and other organic compounds. A single vascular bundle always contains both xylem and phloem tissues.
They do with marine sediments and what type they are i hope this help you out
